JP2009280320A - Conveying device, recording apparatus equipped with conveying device and conveying method for recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a conveying device, a recording apparatus equipped with the conveying device and a conveying method for a recording medium capable of improving suction efficiency of a suction means and conveying efficiency of the recording medium. <P>SOLUTION: The conveying device comprises a support stand 27 formed with a plurality of suction holes 29, a fan generating negative pressure inside the suction holes 29, valves 37 regulating the air flow inside the respective suction holes 29, rotary shafts 40 and cam members 41 switching an opened state and a closed state of the valves 37, a conveyor belt 23 conveying paper 12 from the upstream side in the conveying direction to the downstream side, a paper end sensor detecting the paper 12 conveyed by the conveyor belt 23, and a control part activating the cam members 41 based on the detected result of the paper end sensor, wherein the control part activates the cam members 41 so that the valves 37 are switched to an opened state one by one from the upstream side in the conveying direction based on the detection result of the leading end of the paper 12, and activates the cam members 41 so that the valves 37 are switched to a closed state one by one from the upstream side in the conveying direction based on the detection result of the trailing end of the paper 12. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a transport apparatus, a recording apparatus including the transport apparatus, and a recording medium transport method.

  2. Description of the Related Art Conventionally, an ink jet printer (hereinafter referred to as “printer”) is widely known as a recording apparatus that attaches a recording material (ink) to a target. This printer performs printing (recording) on a recording medium as a target by ejecting ink (liquid) supplied to the recording head from nozzles formed on the recording head.

  In such a printer, in order to transport the recording medium, the recording medium is placed on a transport belt having a plurality of suction holes, and a negative pressure is generated in the suction holes to attract the recording medium to the transport belt. I am letting. However, in such a printer, since a plurality of suction holes communicate with a fan (suction means) that generates a negative pressure in the suction holes, air is sucked from the suction holes that are not covered with the recording medium. The suction efficiency was reduced.

On the other hand, in Patent Document 1, for example, when the sensor detects the passage of the recording medium to be transported, the suction hole is gradually slid by sliding the wind shielding plate that has closed the suction hole in accordance with the passage of the recording medium. The suction efficiency is improved by selectively generating a negative pressure only in the suction holes which are opened and covered with the recording medium.
JP 2004-216651 A

  By the way, in the case of the printer of Patent Document 1, the suction hole is switched between closing and opening using a single wind shield. For this reason, the air shielding plate cannot be returned to the initial position because the suction state must be maintained during the conveyance of the recording medium. Therefore, when continuously transporting the recording medium, after sending the previous recording medium to the downstream side, the windshield plate is returned to the initial position, and again the windshield plate is moved to the next recording medium passing timing. I was trying to start the slide. For this reason, when a plurality of recording media are continuously conveyed, a time lag occurs, and the conveyance efficiency is low.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a transport apparatus capable of improving the suction efficiency of the suction means and the transport efficiency of the recording medium, a recording apparatus including the transport apparatus, and a recording apparatus. It is to provide a method for transporting a medium.

  In order to achieve the above object, a transport apparatus according to the present invention includes a support member having a support surface capable of supporting a recording medium and having suction openings of a plurality of suction holes formed on the support surface; A suction means for sucking air from the suction opening by generating a negative pressure in the hole, and provided in correspondence with each of the suction holes, and in the first valve state, the suction hole is driven when the suction means is driven. And a switch for switching the valve state of the valve in the second valve state, which inhibits the air flow in the suction hole when the suction means is driven than in the first valve state. And a conveying means for conveying the recording medium sucked to the support surface side based on the negative pressure in the suction hole from the upstream side to the downstream side in the conveying direction, and being conveyed by the conveying means Detection means for detecting the recording medium, and the detection Control means for operating the switching means based on the detection result of the stage, and the control means corresponds to the suction hole at a position where the leading edge of the recording medium passes during the conveyance of the recording medium by the conveying means. The valve state of the valve is switched to the first valve state in accordance with the passage timing of the front end of the recording medium, and the valve state of the valve corresponding to the suction hole at the position where the rear end of the recording medium passes Operates the switching means so as to switch to the second valve state in accordance with the passage timing of the rear end of the recording medium.

  According to this configuration, the switching means switches between the first valve state and the second valve state of the valve in accordance with the passing timing of the conveyed recording medium, so that the suction opening is selective only to the suction hole covered with the recording medium. A negative pressure can be generated. For this reason, it is possible to suppress the suction of air from the suction holes whose suction openings are not covered with the recording medium, thereby improving the suction efficiency. Further, since the suction force can be similarly applied over the entire recording medium including the front end and the rear end of the recording medium, the recording medium can be stably conveyed in a state where the movement of the recording medium is suppressed. .

  Further, when the next recording medium is continuously conveyed following the previous recording medium, the valve is switched to the second valve state in accordance with the passage of the rear end of the previous recording medium, and the leading end of the next recording medium is The valve can be switched to the first valve state in accordance with the passage. Therefore, for example, unlike a conventional conveyance device that slides a single wind shielding plate that can block all the suction openings of a plurality of suction holes in accordance with the passing timing of a conveyed target, a plurality of recording media It is possible to improve the conveyance efficiency by reducing the waiting time when continuously conveying.

  The conveying device of the present invention further includes an air flow path that guides air sucked from the suction opening of the suction hole to the suction means based on driving of the suction means, and the air flow path is connected to the valve. The volume of the first negative pressure chamber, which is divided between the suction means and the valve, is divided into a first negative pressure chamber and a second negative pressure chamber with the arrangement position as a boundary. Is larger than the volume of the second negative pressure chamber formed between the two.

  According to this configuration, by switching the valve from the second valve state to the first valve state, an atmospheric pressure state is established via the first negative pressure chamber in which negative pressure is accumulated at that time and the suction opening. When communicating with the second negative pressure chamber, the volume of the first negative pressure chamber is larger than the volume of the second negative pressure chamber, so that the degree of pressure increase in the first negative pressure chamber can be reduced. . Therefore, even if the first negative pressure chamber and the second negative pressure chamber communicate with each other and the pressure rises, the pressure that has risen is such a negative pressure that is necessary to suck the recording medium toward the support surface. Can be recovered in a short time. In addition, by switching the valve from the second valve state to the first valve state, a large suction force can be suddenly applied to the recording medium. For example, the recording medium is deformed and a part of the supporting surface is supported. Even when the user is away from the recording medium, the recording medium can be sucked easily.

  In the transport apparatus according to the present invention, the support member includes a plurality of suction hole arrays in which the plurality of suction holes extend along a direction orthogonal to the transport direction of the recording medium, and are spaced from each other in the transport direction of the recording medium. The switching means switches the valve state of the valve for each of the suction hole rows.

  For example, when transporting a recording medium whose front end and rear end in the transport direction are parallel to each other like a rectangular recording medium, the front end and rear end of the recording medium are orthogonal to the transport direction. Therefore, according to this configuration, by switching the valve state for each valve corresponding to the suction hole array extending in the direction orthogonal to the transport direction, the suction efficiency and the transport efficiency can be improved with simple control.

  In the transport apparatus of the present invention, the switching unit includes a rotation shaft that the control unit rotates based on a detection result of the detection unit, and a cam member that is provided on the rotation shaft so as to be integrally rotatable. The cam member displaces the valve body of the valve between a first position corresponding to the first valve state and a second position corresponding to the second valve state based on the rotation of the rotating shaft.

According to this configuration, since the valve body is displaced to the first position and the second position by rotating the cam member, the responsiveness of switching between the first valve state and the second valve state of the valve can be improved. .
In the transport device of the present invention, the cam member has a contact portion that contacts the valve body at the time of displacing the valve body to the first position in at least one place in the rotation direction of the rotary shaft, The rotating shaft is provided with a plurality of types of the cam members having different numbers of the contact portions, and the control means is determined based on the size of the recording medium in a direction orthogonal to the conveyance direction of the recording medium. The rotation shaft is rotated within the range of the rotation angle.

  According to this configuration, the cam member rotates integrally with the rotation shaft, whereby the contact portion contacts the valve body and displaces the valve body to the first position. Therefore, by using a plurality of types of cam members having different numbers of contact portions, the number of switchings for switching between the first valve state and the second valve state during one rotation of the rotating shaft can be made different for each valve. Can do. Accordingly, only the valve corresponding to the suction hole covered with the recording medium is switched to the first valve state by rotating the rotation shaft within the range of the rotation angle corresponding to the size of the recording medium in the direction orthogonal to the transport direction. be able to.

In the transport device of the present invention, the switching means is a solenoid that displaces the valve body of the valve between a first position corresponding to the first valve state and a second position corresponding to the second valve state. .
According to this configuration, since the valve body is displaced to the first position and the second position by the solenoid, the responsiveness of switching between the first valve state and the second valve state of the valve can be improved.

  In the transport apparatus according to the present invention, the control unit corresponds to the suction hole when the suction opening of the suction hole is covered by the recording medium transported from the upstream side to the downstream side for each suction hole. The switching means is operated to switch the valve to the first valve state.

  According to this configuration, the valve in the second valve state switches the valve to the first valve state when the suction opening of the corresponding suction hole is covered with the recording medium. Therefore, the suction of air from the gap between the recording medium and the suction opening, which occurs when the recording medium is switched to the first valve state while partially covering the suction opening of the suction hole, is preferably sucked. can do.

  In the transport device of the present invention, the transport means is a transport belt in which a communication hole that can communicate with the suction hole by moving while sliding on the support surface of the support member is formed.

  According to this configuration, since the recording medium can be conveyed while adsorbed on the conveyance belt, the recording medium can be conveyed at the same speed as the conveyance belt regardless of the material such as the ease of elongation or bending of the recording medium. can do. Therefore, the conveyance speed of the recording medium can be easily obtained from the conveyance speed of the conveyance belt.

The recording apparatus of the present invention includes a recording unit that performs recording by attaching a recording material to the recording medium, and a conveying apparatus configured as described above that conveys the recording medium.
According to this configuration, since the whole including the front end and the rear end in the conveyance direction of the recording medium can be adsorbed, the movement of the recording medium on the support surface is suppressed, and the deviation of the attachment position of the recording material is suppressed. be able to. Further, since the recording medium can be gradually sucked from the leading end, even when a recording medium that absorbs the recording material and expands and deforms is conveyed, generation of wrinkles caused by kinking can be suppressed.

  In the recording medium transport method of the present invention, the recording medium supported by the support surface of the support member in which the suction openings of the plurality of suction holes are formed is sucked by the negative pressure generated in the suction holes and the support is performed. A method of transporting a recording medium transported from the upstream side to the downstream side in the transport direction while supporting the surface, wherein the suction hole at a position through which the leading end of the transported recording medium passes passes through the suction hole. Switching to a first state in which the flow is allowed, and switching the suction hole at a position through which the rear end of the recording medium passes to a second state in which the flow of air in the suction hole is inhibited. It was.

  According to this structure, the same effect as the said conveying apparatus can be acquired.

(First embodiment)
DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment in which an ink jet printer embodies a transport apparatus, a recording apparatus including the transport apparatus, and a recording medium transport method according to the present invention will be described with reference to the drawings. In the following description, the terms “vertical direction”, “front / rear direction”, and “left / right direction” refer to the directions indicated by arrows in FIGS.

  As shown in FIG. 1, an ink jet printer (hereinafter referred to as “printer”) 11 as a recording apparatus includes a transport mechanism 13 for transporting a rectangular sheet 12 as a recording medium. The transport mechanism 13 includes a first transport unit 15 that transports the paper 12 fed from the paper feed tray 14 positioned on the upstream side (left side) in the transport direction to the downstream side (right side), and the first transport unit 15 The paper 12 is transported further downstream and is composed of a second transport unit 17 serving as a transport device that discharges the paper 12 to a paper discharge tray 16.

  Each of the conveying units 15 and 17 is driven to rotate by a driving force of a motor (not shown) and the first driving pulley 18 and the second driving pulley 19 whose axes are parallel to each other, and the axis of each driving pulley 18 and 19 Each of the first driven pulley 20 and the second driven pulley 21 is rotatable around a parallel axis. Further, an endless first transport belt 22 is stretched between the first drive pulley 18 and the first driven pulley 20, and between the second drive pulley 19 and the second driven pulley 21. The second endless conveyor belt 23 is stretched over. Then, the conveying belts 22 and 23 rotate in accordance with the rotational driving of the corresponding drive pulleys 18 and 19 so that the paper 12 fed from the paper feeding tray 14 is placed on the first conveying belt 22. In this state, the paper is transported from the first transport unit 15 to the second transport unit 17 and further transported to the paper discharge tray 16 while being placed on the second transport belt 23.

That is, the second drive pulley 19, the second driven pulley 21, and the second transport belt 23 each function as a transport unit.
Further, as shown in FIG. 1, at the position above the first conveyance belt 22 in the first conveyance unit 15, it is placed on the surface of the sheet 12 being placed on the first conveyance belt 22 and being conveyed. A recording head 24 is disposed as recording means for ejecting ink as a recording material. From this recording head 24, for example, ink containing water such as dye ink is ejected, and the ink adheres to the surface of the paper 12, thereby forming a recording processing region 12 a (see FIG. 2) on the surface of the paper 12. It comes to form.

  That is, a plurality of nozzle rows (not shown) along the width direction (front-rear direction) of the paper 12 are arranged at regular intervals in the transport direction (left-right direction) on the nozzle forming surface 24 a that is the lower surface of the recording head 24. Has been. Then, the recording head 24 performs printing (recording processing) on the paper 12 by ejecting ink so as to cover the entire width direction as the paper 12 passes below the recording head 24. It has become. In this respect, it can be said that the recording head 24 of the present embodiment is a so-called full-line type line head having an overall shape corresponding to the entire width of the paper 12 in a direction orthogonal to the conveyance direction of the paper 12.

  Further, drying of the paper 12 transferred from the first conveying belt 22 to the second conveying belt 23 is promoted to a position upstream of the second conveying unit 17 and above the second conveying belt 23. For this purpose, a heatable heater 25 is provided. The heater 25 is an infrared heater that radiates infrared rays to the paper 12, and the surface of the paper 12 on which the ink is adhered to the recording processing area 12 a of the paper 12 that has been penetrated by the ink ejected from the recording head 24 ( The surface is heated without contact.

  Moreover, in each conveyance part 15 and 17, between the 1st drive pulley 18 and the 1st driven pulley 20 and between the 2nd drive pulley 19 and the 2nd driven pulley 21, the upper surface (support surface) is planar. A formed first support base 26 and a second support base 27 as a support member are provided. And when each conveyance belt 22 and 23 carries out the revolving motion, the back surface of the belt part which mounts the paper 12 in each conveyance belt 22 and 23, and conveys it downstream (from the left side to the right side), respectively corresponds support. The bases 26 and 27 are in sliding contact with the upper surfaces (support surfaces).

  Accordingly, the sheet 12 conveyed while being placed on the respective conveyor belts 22 and 23 is supported on the upper surfaces (support surfaces) of the respective support bases 26 and 27 corresponding to the respective conveyor belts 22 and 23. It will be.

  As shown in FIG. 1, in the transport mechanism 13, a plurality of zones are sequentially set on the downstream side from the recording zone facing the recording head 24 in the transport path of the paper 12 by the transport belts 22 and 23. First, on the downstream side of the recording zone, there is a first transport zone A for transporting the paper 12 on which the ink is adhered to the recording processing area 12a by ink ejection from the recording head 24 in the recording zone to the position where the heater 25 is disposed. It is set to be continuous with the recording zone. Further, on the downstream side of the first transport zone A, a heating zone B including a heater 25 capable of heating the paper 12 is set to be continuous with the first transport zone A.

  Further, on the downstream side of the heating zone B, a second transport zone C for transporting the paper 12 whose ink evaporation from the recording processing region 12a is promoted by heating in the heating zone B to the second support base 27 is the heating zone. It is set to be continuous with B. Further, on the downstream side of the second transport zone C, a restraining zone D for restraining the paper 12 in a planar state on the second support table 27 is set so as to be continuous with the second transport zone C.

  Moreover, in each conveyance part 15 and 17, each conveyance belt 22 and 23 and each support stand 26 and 27 are each formed with the some hole. However, since the formation modes of these holes are the same in each of the conveyance units 15 and 17, in the following, they are respectively formed on the second conveyance belt 23 and the second support 27 in the second conveyance unit 17 based on FIG. The hole formation aspect of each hole made will be described.

  As shown in FIG. 2, the second transport belt 23 is formed with a large number of air holes 28 so as to pass through the front surface 23 a on which the paper 12 is placed and the back surface in sliding contact with the second support base 27. Yes. These vent holes 28 are regularly arranged so that a plurality of rows of vent holes 28a along the front-rear direction are formed at predetermined intervals in the left-right direction. The vent hole 28 and the vent hole row 28 a as described above are also formed on the first transport belt 22 in the first transport unit 15.

  In addition, the second support base 27 includes a plurality of suction hole arrays 29a extending in the front-rear direction, and a plurality of suction holes 29 penetrating the second support base 27 in the vertical direction (thickness direction of the second support base 27). It is formed at a predetermined interval in the left-right direction. Each suction hole 29 is in a position corresponding to each ventilation hole 28 of the second transport belt 23 in the front-rear direction and wider than each ventilation hole 28 in the left-right direction (for example, about three times). It forms so that it may penetrate between the support surface 27a and the lower surface 27b (refer FIG. 3) of the 2nd support stand 27 in the position where the space | interval was provided. Note that the opening on the support surface 27a side in each suction hole 29 is formed in an opening 30 as a long groove-like suction opening along the left-right direction. The suction holes 29 and the suction hole array 29 a as described above are also formed in the first support base 26 in the first transport unit 15.

  As shown in FIGS. 1 and 2, below the first support base 26, a first suction part 31 having a box shape for sucking the inside of each suction hole 29 is provided on the lower surface side of the first support base 26. Are provided so as to cover the openings of the respective suction holes 29. A second suction part 32 having a box shape for similarly sucking the inside of each suction hole 29 is provided below each second support base 27, and each suction hole 29 on the lower surface 27 b side of the second support base 27. Is provided so as to cover the opening.

  Further, one fan 33 is provided in the first suction part 31, and three fans 33 as suction means are provided in the second suction part 32. As each fan 33 is driven, the suction holes 29 are sucked and become negative pressure, so that the conveying belts 22, through the ventilation holes 28 communicated through the long groove-like openings 30 of the suction holes 29. A downward suction force (binding force) is applied to the paper 12 placed on the paper 23.

  As shown in FIG. 3, the substantially cylindrical suction hole 29 formed in the second support base 27 has a step so that the diameter near the support surface 27a is larger than the diameter near the lower surface 27b sharing the center. It is formed in a shape. The step portion of the suction hole 29 is formed in a tapered shape so that the diameter gradually increases from the lower surface 27b side to the support surface 27a side, thereby forming a substantially frustoconical valve seat 35 having a tapered surface. Yes.

  Then, above the valve seat 35, it abuts against the tapered surface of the valve seat 35 to block the air flow in the suction hole 29 (first state of the suction hole 29), and away from the valve seat 35. A substantially frustoconical valve body 36 is provided that allows air flow in the suction hole 29 (second state of the suction hole 29). That is, the valve body 36 and the valve seat 35 constitute a valve 37. Note that the maximum diameter portion of the valve body 36 is larger than the maximum diameter portion of the valve seat 35. Therefore, when the valve body 36 is seated on the valve seat 35, the valve body 36 is locked by the valve seat 35.

  Further, a cylindrical rod member 38 extends downward from the valve body 36, and the valve body 36 and the rod member 38 can be integrally displaced. The diameter of the rod member 38 is smaller than the diameter near the lower surface 27 b of the suction hole 29. Further, the rod member 38 is inserted through the suction hole 29, and has a length that protrudes from the opening on the lower surface 27b side when the valve body 36 is in the second position where the valve body 36 is in contact with the valve seat 35. Yes.

  On the other hand, in the first negative pressure chamber 39 located between each valve 37 of the second suction part 32 and the fan 33, a rotating shaft 40 extending along the width direction (front-rear direction) of the suction hole row 29a is provided. It is provided corresponding to each suction hole row 29a so as to be longer than the width of the suction hole row 29a. A plurality of disc-shaped cam members 41 that rotate integrally with the rotation shaft 40 are attached to the rotation shaft 40 so as to rotate integrally with the rotation shaft 40 at positions corresponding to the respective valves 37 in the front-rear direction. (See FIGS. 5 and 6). Each of these cam members 41 is an eccentric cam, and their phases are aligned. That is, when the contact portion 42 where the distance from the rotation shaft 40 to the cam surface in one cam member 41 is the largest is on the lower side of the rotation shaft 40, similar contact portions 42 in the other cam members 41 also rotate. It is located below the shaft 40.

  When the cam member 41 rotates along with the rotation of the rotary shaft 40, each contact portion 42 of each cam member 41 contacts the rod member 38 to push the rod member 38 and the valve body 36 upward, thereby The valve body 36 and the valve seat 35 are separated from each other, and the valve 37 is switched to the valve open state (first valve state). That is, the rotating shaft 40 and the cam member 41 function as switching means.

  On the other hand, a space between the valve 37 and the support surface 27a is a second negative pressure chamber 43 that communicates with the first negative pressure chamber 39 when the valve 37 is opened. The second negative pressure chamber 43 has a volume of the second negative pressure chamber 43 in the suction hole row 29a in which the communication state and the non-communication state with respect to the first negative pressure chamber 39 are switched by one rotating shaft 40. The total is smaller than the volume of the first negative pressure chamber 39 communicated. In the present embodiment, the first negative pressure chamber 39 and the second negative pressure chamber 43 that are partitioned vertically from the position where the valve 37 is disposed are used to drive the opening 30 of the suction hole 29 based on the driving of the fan 33. An air flow path for guiding the air sucked from the air to the fan 33 is configured.

  As shown in FIG. 4, the printer 11 is provided with a control unit 44 as a control unit that performs overall control of the operating state of the printer 11. The control unit 44 functions as a central processing unit in a digital computer including a CPU 45 that executes various calculations, a ROM 46 that stores programs and preset information, and a RAM 47 that temporarily stores input information. Configured.

  Based on the detection result of the rotation speed counter 48 that counts the rotation speed of the second drive pulley 19 and the paper edge sensor 49 that detects the paper edge of the paper 12 conveyed through the second conveyance section 17, the control unit 44. The motor 50 for rotationally driving the rotary shaft 40 is driven and controlled.

  That is, the CPU 45 first resets the counter value of the rotation number counter 48 of the rotating second drive pulley 19 to zero. Then, based on the measurement time of the built-in clock, the count value (number of rotations) of the rotation number counter 48 is acquired after a predetermined time and stored in the RAM 47. Thereafter, the transport speed of the paper 12 placed on the second transport belt 23 and transported at the same speed as the second transport belt 23 is set to the thickness of the second drive pulley 19 stored in the ROM 46 or the second transport belt. 23 is calculated from the data such as the thickness of 23 and the count value per unit time and stored in the RAM 47.

  Further, when the leading edge and the trailing edge of the paper 12 are detected by the paper edge sensor 49 provided in the second transport zone C on the upstream side of the second support 27, the CPU 45 is the leading edge or the trailing edge. And the detected time and the detected time are stored in the RAM 47.

  Then, based on these pieces of information stored in the RAM 47, the CPU 45 determines the time during which the leading end of the paper 12 is transported to the downstream end in the transport direction of each opening 30 and the trailing end of the paper 12 is the opening 30. The time for transporting to the upstream end in the transport direction is calculated for each suction hole array 29a. Thereafter, the control unit 44 drives the motor 50 to rotate the rotating shaft 40 at a timing based on the calculation result.

  Next, regarding the operation of the printer 11 of the present embodiment configured as described above, after printing is performed by the recording head 24 in the recording zone, the first transport zone A, the heating zone B, the second transport zone C, The operation when the paper 12 is conveyed so as to sequentially pass through the restriction zone D will be mainly described.

  When printing on the paper 12 in the printer 11, first, the paper 12 is fed from the paper feed tray 14 onto the first transport belt 22, and the transport belt is used to transport the paper 12 downstream. 22 and 23 start a circular motion. Further, the inside of the suction holes 29 of the support bases 26 and 27 is sucked by driving the fans 33 of the suction portions 31 and 32. As a result, a negative pressure is generated in the vent hole 28 located in the region where the paper 12 is placed on the first conveying belt 22 and the suction hole 29 of the support base 26 communicating with the vent hole 28 through a long groove-like opening. Therefore, the paper 12 placed on the first transport belt 22 receives the negative pressure and is transported to the downstream side in a restrained state in which the paper 12 is adsorbed on the first transport belt 22 in a planar shape, and the recording head in the recording zone. Ink is adhered to the recording processing area 12 a by ink ejection from the recording medium 24.

  Subsequently, in the first transport zone A, the paper 12 is transported downstream in an unheated state and an unconstrained state. Therefore, the ink adhering to the recording processing area 12a of the paper 12 gradually permeates and diffuses into the paper 12 during the conveyance, and the recording processing area 12a is expanded and deformed. Note that the recording processing area 12a of the paper 12 in the present embodiment is a rectangular area in which ink adheres in a solid shape, and a non-recording processing area (non-liquid adhesion area) 12b in which no ink adheres around the area. Is surrounded by The non-recording processing area 12b refers to an area where the fibers of the paper 12 are kept connected to each other because no ink adheres to the surface and the ink does not penetrate inside.

  Here, the paper 12 of the present embodiment is a porous material having a liquid absorbing property in which pulp fibers made of wood as a raw material (the main component is cellulose, hereinafter referred to as “fiber”) are stacked so as to form a network structure. Material. Therefore, when ink adheres to the paper 12, the hydrophilic fiber absorbs the ink solvent of the ink (an organic solvent such as moisture or alcohol) and swells to increase the volume of the recording processing region 12a. Further, since the ink that is not absorbed by the fibers penetrates into the gaps between the fibers in the paper 12 and cuts the hydrogen bonds between the fibers, the fibers in the recording processing region 12a are in a state of being relatively movable. For this reason, the recording processing area 12a is expanded and deformed by the swollen fibers pressed against each other. Therefore, the paper 12 on which the recording processing area 12a is formed is separated from the surface of the first conveying belt 22 with the penetration and diffusion of ink. It is deformed so as to be separated from each other and becomes a wave shape along the conveying belt 22 (so-called cockling phenomenon).

  Next, the paper 12 on which such undulation has occurred is transferred from the first conveyance belt 22 to the second conveyance belt 23, thereby being conveyed from the first conveyance zone A to the heating zone B. Then, in the heating zone B, the recording process area 12a of the paper 12 is heated by the heater 25, and the evaporation of ink from the recording process area 12a is promoted. For this reason, the recording processing area 12a of the paper 12 is in a dry state due to the evaporation of the ink, and the increase in volume due to the penetration and diffusion of the ink until then stops, so that the degree of expansion is suppressed.

  At this time, the heater 25 heats the paper 12 in a non-contact manner with respect to the surface of the paper 12 placed on the surface 23a of the second transport belt 23 (that is, the surface to which ink as a liquid adheres). Further, since the support bases 26 and 27 are not positioned in the heating zone B in the conveyance path of the paper 12, the paper 12 may receive a negative pressure on the surface 23 a of the second conveyance belt 23 in the heating zone B. It is heated while being conveyed in an unconstrained state where it is simply placed. Therefore, no restraining force in the direction of reducing the degree of expansion is applied to the expanded and deformed recording processing area 12a, so that no wrinkles occur on the paper 12.

  Subsequently, the paper 12 is transported to the second transport zone C while being placed on the surface 23a of the second transport belt 23, and transported downstream in the second transport zone C in an unheated state and an unconstrained state. Is done.

  At this time, the sheet end sensor 49 provided in the second transport zone C inputs the detection result of detecting the passage of the leading end of the sheet 12 to the control unit 44. Then, the control unit 44 calculates the drive timing of the motor 50 corresponding to each rotating shaft 40 of the second transport unit 17.

  In addition, the valve 37 in the previous stage where the paper 12 is conveyed to the restraining zone D is in a closed state (second valve state) as shown in FIG. 5, and the air flow path is blocked by the valve 37. It shall be in That is, the second negative pressure chamber 43 is in an atmospheric pressure state through the opening 30 and the vent hole 28. When the paper 12 is conveyed to the restraining zone D, the control unit 44 drives the motor 50 based on the calculated drive timing and opens the valve 37.

  The drive timing of the motor 50 is such that when the leading end of the paper 12 is transported to a position D1 (see FIG. 3) where the opening 30 is downstream in the transport direction, the suction hole array 29a (the left suction hole in FIG. The motor 50 of the rotary shaft 40 corresponding to the suction hole array formed by the motor 29 is driven. Therefore, the contact portion 42 of the cam member 41 sequentially contacts the rod member 38 from the upstream side in the transport direction, and the valve 37 is opened. The control unit 44 stops the driving of the motor 50 in a state where the contact portion 42 of the cam member 41 is positioned above the rotation shaft 40 and pushes up the rod member 38. Therefore, the valve 37 of the suction hole 29 located downstream of the position D1 in the transport direction is maintained in the closed state as shown in FIG.

  That is, when the paper 12 is further conveyed from the position D1 and the leading end is located at the position D2, the motor 50 of the rotary shaft 40 corresponding to the suction hole row formed by the right suction holes 29 in FIG. 3 is driven. As shown in FIG. 6, the valve 37 is opened. In this way, each suction hole array 29a can sequentially apply a suction force to the paper 12 from the upstream side as the paper 12 is transported. It is restrained by the surface 23a.

  On the other hand, when the paper end sensor 49 detects the detection result of the passage of the rear end of the paper 12 being input to the control unit 44, the control unit 44 calculates the drive timing of the motor 50 corresponding to each rotation shaft 40 of the paper 12. .

  When the trailing edge of the sheet 12 is conveyed to the restraining zone D, the control unit 44 sequentially drives the motor 50 of each rotary shaft 40 from the upstream side in the conveyance direction based on the calculated drive timing. Then, the abutting portion 42 of the cam member 41 is separated from the rod member 38, and the valve 37 is closed. The control unit 44 stops driving the motor 50 in a state where the contact portion 42 of the cam member 41 is positioned below the rotation shaft 40.

  That is, when the rear end of the sheet 12 is transported to a position D3 (see FIG. 3) that is the upstream end of the opening 30 in the transport direction, the valve corresponding to the left rotation shaft 40 in FIG. 37 is closed.

  Then, at the timing when the sheet 12 is further conveyed and the rear end thereof is positioned at the position D4, the control unit 44 drives the motor 50 corresponding to the right rotation shaft 40 in FIG. 3 to close the valve 37. And

  For this reason, in the restraining zone D, a suction force is applied in order from the front end to the rear end of the paper 12, so that the paper 12 has a recording processing region 12a that is inflated and deformed in a freshly dried state. While being constrained in a planar shape so as to maintain a uniform surface state with the region 12b, it is transported to the downstream side according to the circular motion of the second transport belt 23.

  The paper 12 is naturally dried while the paper 12 is being conveyed, and the ink naturally evaporates from the recording processing area 12a. The recording processing area 12a and the non-recording processing area 12b are naturally dried while maintaining a uniform surface. The cockling phenomenon that has occurred due to the expansion and deformation of the processing region 12a disappears.

  When the next sheet 12 is transported following the transport of the previous sheet 12, the second transport unit 17 is driven again in the same procedure as described above, and the valve 37 in the closed state is moved to the next sheet 12. The valve is opened again in accordance with the passage of the tip.

According to the first embodiment, the following effects can be obtained.
(1) The rotary shaft 40 to which the cam member 41 is attached is rotated in accordance with the timing at which the conveyed paper 12 passes through the suction hole array 29a. Therefore, the abutting portion 42 of the cam member 41 that rotates integrally with the rotating shaft 40 abuts on the rod member 38 to switch the valve 37 between the valve open state and the valve closed state. A negative pressure can be selectively applied only to the suction holes 29 that communicate with each other. And it can suppress that air is attracted | sucked from the suction hole 29 connected with the ventilation hole 28 which is not covered with the paper 12, and can improve suction efficiency. In addition, since the suction force can be similarly applied to the entire sheet 12 including the front end and the rear end of the sheet 12, the sheet 12 can be stably conveyed in a state in which the play is suppressed.

  Further, when the next paper 12 is continuously conveyed following the previous paper 12, the valve 37 that is switched to the closed state in accordance with the passage of the previous paper 12 is matched with the passage of the next paper 12. The valve can be switched to the open state. Therefore, when conveying a plurality of sheets 12 continuously, the waiting time can be shortened and the conveyance efficiency can be improved.

  (2) In the state where the valve 37 is closed, the first negative pressure chamber 39 which is sucked by the fan 33 and accumulates the negative pressure, and the atmospheric pressure via the vent hole 28 when the valve 37 is in the closed state. The second negative pressure chamber 43 in a state is in communication by opening the valve 37. At this time, by making the volume of the first negative pressure chamber 39 larger than the volume of the second negative pressure chamber 43, the degree of increase in the pressure of the first negative pressure chamber 39 can be reduced. Therefore, even if the first negative pressure chamber 39 and the second negative pressure chamber 43 communicate with each other and the pressure increases, the increased pressure can be recovered in a short time to the negative pressure necessary for the adsorption of the paper 12. Can do. In addition, since a large suction force can be abruptly applied to the paper 12, ink adheres and expands and deforms, and a part of the paper 12 away from the surface 23a can be sucked easily.

  (3) The rectangular paper 12 was conveyed so that the front end and the rear end thereof were parallel to the suction hole row 29a, and the opening / closing of the valve 37 was switched for each suction hole row 29a by the drive control of the motor 50. Therefore, the suction efficiency and the conveyance efficiency can be improved with simple control compared to the case where the valve state of the valve 37 is individually controlled.

  (4) By rotating the cam member 41, the first position where the valve element 36 is separated from the valve seat 35 and the second position where the valve body 35 abuts on the valve seat 35 are displaced. Therefore, the responsiveness of switching between the valve open state and the valve closed state of the valve 37 can be improved.

  (5) The valve 37 in the closed state switches the valve 37 to the open state when the corresponding opening 30 of the suction hole 29 is covered with the paper 12. Therefore, the suction of air from the gap between the paper 12 and the opening 30 that occurs when the paper 12 is switched to the valve opening state with the paper 12 partially covering the opening 30 of the suction hole 29 is suppressed. Suction can be suitably performed.

  (6) Since the paper 12 is transported in a state of being adsorbed on the transport belt 23, for example, even when a film that is easily stretched or bent is transported instead of the paper 12, it can be transported at the same speed as the transport belt 23. it can. Therefore, the transport speed of the transported paper 12 (film or the like) can be easily obtained from the transport speed of the transport belt.

(7) Since the paper 12 is gradually sucked from the tip, even when the paper 12 that absorbs ink and expands and deforms is conveyed, the generation of wrinkles due to kinking can be suppressed.
(8) At the timing when the leading edge of the paper 12 is conveyed to the support base 27, first, the valve 37 corresponding to the suction hole row 29a located on the most upstream side is opened, and the leading edge of the paper 12 is adsorbed to the conveying belt 23. Let For this reason, the leading end of the sheet 12 is adsorbed across the width direction, and the sheet 12 is placed on the transport belt 23 so as to be pulled by the leading end, thereby suppressing distortion and bending when being placed. Thus, the sheet can be conveyed in a straight state with respect to the conveying direction, and the reliability of conveying the paper 12 can be improved.

  (9) The opening and closing of the valve 37 is switched using the cam member 41 and the rotating shaft 40. Therefore, the first negative pressure chamber 39 and the second negative pressure chamber 43 are required to communicate with each other when the valve 37 is opened according to the differential pressure between the first negative pressure chamber 39 and the second negative pressure chamber 43. A flow path becomes unnecessary. Therefore, the negative pressure generation capability of the fan 33 can be set to a level that does not include the negative pressure loss from the fine flow path.

(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIGS. The second embodiment differs from the first embodiment only in that the shape of the cam member is changed, and the other configurations are the same, so the same components are the same. A detailed description thereof will be omitted by attaching a reference numeral.

  As shown in FIGS. 7A to 7C and FIG. 8, a plurality of types (three types in the present embodiment) of cam members 51, 56, and 60 having different shapes are provided on the rotating shaft 52 in the present embodiment. 52 is supported so as to be integrally rotatable with respect to 52.

  As shown in FIG. 7A, the first cam member 51 is formed with a through-hole 53 through which the rotary shaft 52 is inserted in the central portion. The first cam member 51 includes three contact portions having a large distance from the center to the cam surface, that is, a first contact portion 54a, a second contact portion 54b, and a third contact portion 54c. Have. In addition, the distance from the center of each contact part 54a-54c is equal, respectively. The contact portions 54a to 54c are formed with an interval of 120 degrees from each other, and the first non-contact portion 55a and the second contact portion 54b are formed between the third contact portion 54c and the second contact portion 54b. A second non-contact portion 55b is provided between the contact portion 54b and the first contact portion 54a, and a third non-contact portion 55c is provided between the first contact portion 54a and the third contact portion 54c. Each non-contact part 55a-55c has a smaller distance from the center than each contact part 54a-54c.

  As shown in FIG. 7B, the second cam member 56 is formed with a through hole 57 for inserting the rotating shaft 52 in the center portion. The second cam member 56 has a first contact portion 58a and a second contact portion 58b whose distance from the center to the cam surface is equal to the contact portions 54a to 54c of the first cam member 51. is doing. Each contact portion 58a, 58b is formed with an interval of 120 degrees on one side and 240 degrees on the other side, and both sides thereof are a first non-contact portion 59a and a second non-contact portion 59b. .

  Therefore, the shape of the contact portions 58a and 58b and the non-contact portions 59a and 59b of the second cam member 56 is any one of the contact portions 54a to 54c of the first cam member 51, and It matches the shape of the non-contact portions 55a to 55c sandwiched between the two contact portions.

  As shown in FIG. 7C, the third cam member 60 is formed with a through hole 61 for inserting the rotation shaft 52 in the center portion. The distance from the center of the third cam member 60 to the cam surface is the contact portions 54a to 54c, 58a and 58b of the first cam member 51 and the second cam member 56 and the non-contact portions 55a to 55a. One abutment portion 62a and one non-abutment portion 63a, each equal to 55c, 59a, and 59b, are provided. The shape of the contact portion 62a of the third cam member 60 matches the shape of the contact portions 54a to 54c, 58a, and 58b of the other cam members 51 and 56.

  As shown in FIG. 8, the cam members 51, 56, 60 are attached to the rotating shaft 52 so that the phases are aligned, and rotate integrally with the rotation of the rotating shaft 52. That is, the straight line connecting the first contact portions 54 a, 58 a, 62 a of the cam members 51, 56, 60 is parallel to the rotation shaft 52. Therefore, the straight line connecting the first cam member 51 and the second contact portions 54 b and 58 b of the second cam member 56 is also parallel to the rotation shaft 52.

  Therefore, assuming that the state shown in FIG. 8 is the initial state (0 degree), when the rotation shaft 52 is rotated 60 degrees in the counterclockwise direction indicated by the arrow in FIG. The contact portions 55a, 59a, and 63a are located above the rotation shaft 52. When the rotating shaft 52 is further rotated 60 degrees (120 degrees from the initial position), the second contact portions 54b and 58b of the first cam member 51 and the second cam member 56 are positioned upward, and the third cam member As for 60, the 1st non-contact part 63a is located in the upper part.

  When the rotating shaft 52 is further rotated by 120 degrees (240 degrees from the initial position), the first non-contact portion 55b of the first cam member 51 and the second cam member 56 is rotated by 180 degrees from the initial position. , 59b pass above the rotating shaft 52, and the first contact portions 54a, 58a, 62a of the cam members 51, 56, 60 are positioned above. Further, when the rotation shaft 52 is further rotated 120 degrees (360 degrees from the initial position), the third non-contact portion 55c of the first cam member 51 and the second cam member 56 are rotated when the rotation shaft 52 is rotated 300 degrees from the initial position. In addition, the first non-contact portions 59a and 63a of the third cam member 60 pass above the rotation shaft 52, and the third contact portion 54c of the first cam member 51 is positioned above the rotation shaft 52 again. It becomes the same state as the state.

  In the support base 64 of the present embodiment, as shown in FIG. 9, suction hole rows 29 a formed so that seven suction holes 29 are arranged along the front-rear direction have an interval in the left-right direction. A plurality of arrays are formed. A plurality of rotating shafts 52 extending in the front-rear direction are provided below each suction hole row 29a so as to individually correspond to each suction hole row 29a. A plurality of cam members 51, 56, and 60 are attached to each rotary shaft 52 in phase so as to rotate integrally with the rotary shaft 52 in accordance with the size of the sheets 65 a to 65 c to be conveyed.

  In the present embodiment, three types of paper 65a to 65c having different sizes in the width direction orthogonal to the transport direction may be transported. That is, the size enough to cover the vent hole 28 communicating with the three suction holes 29 in the front-rear direction (size 1), the size enough to cover the vent hole 28 communicating with the five suction holes 29 (size 2), and There are cases where three types of sheets 65a to 65c each having a size (size 3) that covers the vent hole 28 communicating with the seven suction holes 29 are conveyed. Therefore, the rotary shaft 52 includes one third cam member 60, one second cam member 56, three first cam members 51, one second cam member 56, and one third cam member 60. In this order, the suction holes 29 are attached one by one from the front side to the rear side.

  That is, the cam members 51, 56, 60 are attached to the rotary shafts 52 so that the same cam members 51, 56, 60 are aligned along the transport direction. Specifically, in the substantially central portion in the longitudinal direction of the rotation shaft 52 along the width direction of the sheets 65a to 65c, there are three positions corresponding to the three valves 37 positioned in the region through which the size 1 sheet 65a passes. A first cam member 51 is attached. Then, in the longitudinal direction of the rotation shaft 52, outside the area (front and rear sides) through which the size 1 sheet 65a passes, the size 1 sheet 65a does not pass, and the size 2 and size 3 sheets 65b and 65c. Two second cam members 56 are attached to the positions corresponding to the two valves 37 located in the passing region so as to be one each at the front and rear. Furthermore, in the longitudinal direction of the rotation shaft 52, outside the area (front and rear sides) through which the size 2 sheet 65b passes, the size 1 and size 2 sheets 65a and 65b do not pass, and the size 3 sheet 65c. Two third cam members 60 are attached to the positions corresponding to the two valves 37 located in the region through which only one passes, so that there is one each in the front and rear.

  Then, the control unit 44 controls the paper 65a to 65 according to the rotation angle based on the initial state of the rotation shaft 52 obtained from the detection result of the rotation angle detection sensor (not shown) and the paper width input from the paper edge sensor 49. The motor 50 of the rotary shaft 52 is controlled based on the table stored in the ROM 46 before the 65c is conveyed.

Next, the operation of the printer 11 of the present embodiment configured as described above will be described focusing on the operation when the sheets 65a to 65c having different sizes in the front-rear direction are conveyed.
As shown in FIG. 9, when transporting the size 1 paper 65 a, first, the control unit 44 drives and controls the motor 50 based on the table stored in the ROM 46 and is rotated 300 degrees from the initial state. The rotation shaft 52 is rotated so that the third non-contact portion 55c of the first cam member 51 and the first non-contact portions 59a and 63a of the second and third cam members 56 and 60 are positioned upward. Let

  Then, based on the drive timing calculated in the same manner as in the first embodiment, the motor 50 is driven so that the rotating shaft 52 rotates by 60 degrees counterclockwise. That is, the rotary shaft 52 is rotated 60 degrees counterclockwise in accordance with the leading end of the sheet 65a passing above the suction hole 29 located in the area through which the conveyed sheet 65a passes. Then, in the first cam member 51, the third contact portion 54c contacts the rod member 38 of the corresponding valve 37, and the three valves 37 positioned at the center portion in the front-rear direction are opened. Therefore, the second negative pressure chamber 43 in the suction hole 29 located in the range where the paper 65a is placed and whose suction opening is covered by the paper 65a communicates with the first negative pressure chamber 39, and the paper A suction force is applied to 65a.

  On the other hand, the four cam members 56 and 60 on the both front and rear sides in the longitudinal direction of the rotating shaft 52 are not in contact with the rod member 38 because the non-contact portions 59a and 63a are positioned above, respectively. The corresponding valve 37 is kept closed. Next, when the rear end of the sheet 65a passes over the three suction holes 29 in the central portion corresponding to the valve 37 that is opened in accordance with the passage of the leading end of the sheet 65a, the passage is stopped. At the same time, the rotation shaft 52 is further rotated 60 degrees. Then, the cam members 51, 56, 60 are arranged such that the first non-contact portions 55 a, 59 a, 63 a are positioned above the rotation shaft 52, and as a result, all the valves corresponding to the suction holes 29 are arranged. 37 is closed.

  As shown in FIG. 10, when transporting the size 2 paper 65b, the control unit 44 first drives and controls the motor 50 based on the table stored in the ROM 46, and rotates it 60 degrees from the initial state. The rotary shaft 52 is rotated so that the first non-contact portions 55a, 59a, 63a of the cam members 51, 56, 60 are positioned upward.

  Then, based on the drive timing calculated in the same manner as in the first embodiment, the motor 50 is driven so that the rotation shaft 52 rotates 60 degrees counterclockwise. Then, as shown in FIG. 10, the second contact portions 54b and 58b of the first and second cam members 51 and 56 are in contact with the rod members 38 of the corresponding valves 37, and are positioned at the center in the front-rear direction. The five valves 37 are opened. Therefore, the second negative pressure chamber 43 in the suction hole 29 located in the range where the paper 65b is placed and whose suction opening is covered with the paper 65b communicates with the first negative pressure chamber 39, and the paper A suction force is applied to 65b.

  On the other hand, the two third cam members 60 at the front and rear ends in the longitudinal direction of the rotating shaft 52 are not in contact with the rod member 38 because the non-contact portions 63a are positioned above, respectively. The valve 37 is kept closed. Then, when the rear end of the sheet 65b passes over the five suction holes 29 in the central portion corresponding to the valve 37 which is opened in accordance with the passage of the leading end of the sheet 65b, the passage is stopped. At the same time, the rotation shaft 52 is further rotated 60 degrees. Then, the cam members 51, 56, 60 have the second non-contact portions 55 b, 59 b and the first non-contact portion 63 a positioned above the rotation shaft 52, respectively. All the valves 37 corresponding to are closed.

  As shown in FIG. 11, when transporting a sheet 65c having a width (size 3) larger than the width of the vent hole array 28a communicating with the suction hole array 29a, first, the control unit 44 is stored in the ROM 46. The motor 50 is driven and controlled based on the table, and the rotating shaft 52 is rotated so that the motor 50 is rotated 180 degrees from the initial state, so that the second non-contact portion 55b of each cam member 51, 56, 60 is 59b and the first non-contact portion 63a are positioned upward.

  Then, based on the drive timing calculated in the same manner as in the first embodiment, the motor 50 is driven so that the rotation shaft 52 rotates 60 degrees counterclockwise. Then, as shown in FIG. 11, the first abutting portions 54a, 58a, 62a of the cam members 51, 56, 60 abut against the rod members 38 of the corresponding valves 37, and all the valves of the suction hole row 29a 37 is opened. Therefore, the second negative pressure chamber 43 in the suction hole 29 located within the range where the paper 65c is placed and whose suction opening is covered with the paper 65c communicates with the first negative pressure chamber 39, and the paper A suction force is applied to 65c. Then, when the rear end of the sheet 65c passes over the suction holes 29 corresponding to the valves 37 that are opened according to the passage of the leading edge of the sheet 65c, the rotation shaft is aligned with the passage. 52 is further rotated 60 degrees. Then, the cam members 51, 56, 60 have the third non-contact portion 55 c and the first non-contact portions 59 a, 63 a positioned above the rotation shaft 52, respectively. All the valves 37 corresponding to are closed.

Therefore, in this embodiment, the cam members 51, 56, 60 and the rotating shaft 52 function as switching means for switching the valve state of the valve 37.
According to the said 2nd Embodiment, in addition to the effect of (1)-(9) in 1st Embodiment, the following effects can be acquired further.

  (10) The cam members 51, 56, and 60 having the contact portions 54a to 54c, 58a, 58b, and 62a and the non-contact portions 55a to 55c, 59a, 59b, and 63a rotate around the rotation shaft 52. Accordingly, the contact portions 54a to 54c, 58a, 58b, and 62a contact the rod member 38 that is displaced together with the valve body 36 to displace the valve body 36. The cam members 51, 56, 60 attached to the rotary shaft 52 with the same phase are in contact with the contact portions 54 a to 54 c, 58 a, 58 b, 62 a and the non-contact portion 55 a according to the rotation angle of the rotary shaft 52. The positions of .about.55c, 59a, 59b, 63a can be determined. That is, the valve 37 to be opened can be selected by changing the rotation angle of the rotating shaft 52. Therefore, only the valve 37 corresponding to the suction hole 29 covered with the sheets 65a to 65c is opened and closed each time by rotating the rotating shaft 52 within the range of the rotation angle corresponding to each size of the sheets 65a to 65c. Can do.

  (11) By opening only the valve 37 corresponding to the sheet width, the suction of air from the suction holes 29 not covered by the sheets 65a to 65c in the width direction is suppressed. Therefore, the suction efficiency can be improved even when the sheets 65a to 65c having different sheet widths are conveyed.

(Third embodiment)
Next, a third embodiment of the present invention will be described with reference to FIG. The third embodiment is different from the first embodiment only in that the switching means for displacing the valve body is changed, and the other configurations are the same. Constituent parts are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the present embodiment, a cylindrical rod member 38 extending from the valve body 36 in the valve 37 is formed of a magnetic material (for example, iron). Further, a solenoid 66 is provided below the rod member 38 as switching means for changing the magnetic field around the rod member 38.

  That is, the rod member 38 pushed upward by an urging member (not shown) is moved downward against the urging force of the urging member by a magnetic field generated by applying a voltage to the solenoid 66 to be in an excited state. Gravitate. Then, since the valve body 36 moves downward together with the rod member 38 and is seated on the valve seat 35, the valve 37 is closed.

  On the other hand, when the application of voltage to the solenoid 66 is stopped and the demagnetization state occurs, the rod member 38 is pushed upward by the urging force of the urging member. Then, since the valve body 36 moves upward together with the rod member 38 and is separated from the valve seat 35, the valve 37 is opened.

  Further, the control unit 44 calculates the conveyance speed of the paper 12 and stores it in the RAM 47 as in the first embodiment. Further, when the leading edge and the trailing edge of the paper 12 are detected by the paper edge sensor 49, the detection result as to whether the leading edge or the trailing edge is detected and the detected time are stored in the RAM 47.

  Based on these pieces of information stored in the RAM 47, the time during which the leading edge of the sheet 12 is conveyed to the downstream end in the conveying direction of each opening 30 and the trailing edge of the sheet 12 in the conveying direction of each opening 30 are displayed. Each time to be conveyed to the upstream end is calculated. Thereafter, the control unit 44 can switch the excitation state and the demagnetization state of the solenoid 66 at a timing based on the calculation result.

  Next, the operation of the printer 11 of the present embodiment configured as described above will be described focusing on the operation when the paper 12 is conveyed. As a premise for explanation, a voltage is applied to the solenoid 66 corresponding to the suction hole 29 before the paper 12 is conveyed, and the valve 37 is closed as shown on the right side of FIG.

  When the paper 12 is conveyed, the control unit 44 sequentially stops applying the voltage to the solenoid 66 from the upstream side in accordance with the calculated timing. Specifically, at the timing when the leading end of the sheet 12 is transported to the position D1 that is the downstream end of the opening 30 in the transport direction, the application of the voltage to the solenoid 66 on the left side in FIG. Is stopped to the position D2, and the application of the voltage to the right solenoid 66 in FIG. 12 is stopped.

  When the sheet 12 is further conveyed and conveyed to the position D3 where the rear end of the sheet 12 is the upstream end of the opening 30 in the conveying direction, a voltage is applied to the left solenoid 66 in FIG. Further, a voltage is applied to the right solenoid 66 in FIG. 12 at the timing when the rear end of the sheet 12 is conveyed to the position D4.

According to the said 3rd Embodiment, in addition to the effect of (1)-(12) in 1st Embodiment and 2nd Embodiment, the following effects can be acquired further.
(13) By providing a solenoid 66 corresponding to each valve 37 and selecting the application of the voltage, a first position in which the valve body 36 is separated from the valve seat 35 and a second position in which the valve seat 35 is seated are provided. Displaced between. Therefore, the responsiveness of switching between the valve open state and the valve closed state of the valve 37 can be improved.

In addition, you may change the said embodiment as follows.
In each of the above embodiments, the first transport unit 15 may be provided with a switching unit similarly to the second transport unit 17. Thereby, when ink is ejected from the recording head 24, the entire sheet 12 including the leading and trailing edges of the sheet 12 can be reliably adsorbed, so that the movement of the sheet 12 on the surface of the first conveying belt 22 is suppressed. Thus, it is possible to suppress the deviation of the ink adhesion position. Further, when the paper 12 is transported to the first transport belt 22, the leading end of the paper 12 is adsorbed across the width direction, so that distortion and bending that occur during transport are suppressed. For this reason, the stain generated by the ink ejected onto the paper 12 adhering to the transport belt 22 is suppressed, and the print quality can be improved.

  In each of the above embodiments, the printer 11 may include a paper type detection sensor as a detection unit that can detect the type of the paper 12. Alternatively, an operation panel that allows the operator to set the paper type may be provided.

  At this time, the ROM 46 stores a driving mode of the motor 50 corresponding to the paper type. For example, when using the low-stiff paper 12, the cockling is easily eliminated by delaying the suction start time. Therefore, when transporting a sheet 12 having a low stiffness as a sheet type, the second support base 27 on which the sheet 12 that has been inflated and deformed with ink attached is transported is a plurality of valves 37 positioned on the upstream side in the transport direction. By keeping the valve closed, it is possible to suppress a decrease in print quality due to cockling.

  Further, in the cam members 41, 51, 56, 60 located on the upstream side in the transport direction, the contact position with the rod member 38 is shifted from the contact portions 42, 54a to 54c, 58a, 58b, 62a, or the solenoid 66 By reducing the current applied to the paper, the cross-sectional area of the air flow path is reduced, and the suction force applied to the paper 12 is reduced. Can be suppressed.

Thereby, the influence by the material of the paper 12 can be suppressed, and the paper 12 having a different thickness or Japanese paper can be dealt with.
In each of the above embodiments, the paper 12 with the ink attached to the surface thereof by other printing processing such as stencil printing is not transported by the ink from the recording head 24 but is transported onto the support 27 and dried. Also good.

  In each of the above embodiments, a gap may be formed between the valve body 36 and the valve seat 35. That is, the valve 37 does not block the air flow path, but inhibits the flow of air flowing through the air flow path, thereby increasing the flow path resistance of the air flow path and the suction holes not covered by the paper 12. The suction from 29 can be reduced and the suction efficiency can be improved. Furthermore, when the air passes through the gap between the valve body 36 and the valve seat 35, the valve body 36 can be easily separated from the valve seat 35. Therefore, the valve 37 can be easily switched from the closed state to the open state.

In each of the above embodiments, a restricting portion that restricts the displacement of the valve body 36 or a biasing member that biases the valve body 36 downward may be provided.
In each of the above embodiments, the control unit 44 controls the drive of the drive pulleys 18 and 19 based on the transport speed of the paper 12 stored in the ROM 46 and the drive mode of the drive pulleys 18 and 19, and based on the transport speed. Thus, the drive timing of the motor 50 may be calculated.

  In the third embodiment, the paper edge sensor 49 detects the paper edge in the paper width direction, and the voltage to the solenoid 66 is opened so that only the valve 37 corresponding to the suction hole 29 where the paper 12 is positioned in the width direction is opened. The application may be stopped.

  In the third embodiment, a link mechanism that transmits changes in excitation and demagnetization of the solenoid 66 to the rod member 38 may be provided. That is, for example, when a lever is used as the link mechanism, a magnetic body that swings around a fulcrum when the solenoid 66 is excited is provided with a valve 37 that is normally closed using an elastic member that pulls the rod member 38 downward. By pulling, the opposite end of the magnetic body may push up the rod member 38 to open the valve 37.

  In each of the above embodiments, the paper 12 that has been expanded and deformed by the adhesion of ink is embodied in the second transport unit 17 that returns to a flat state, but the present invention transports the paper 12 that is used in other devices. The present invention can also be applied to a transport device.

  In each of the above embodiments, the timing for opening the valve 37 may be the timing at which the leading end of the paper 12 is positioned at the upstream end of the opening 30, and the timing for closing the valve 37 is the timing after the paper 12 is closed. It may be the timing when the end is located at the downstream end of the opening 30.

  In the second embodiment, the number of cam members 51, 56, 60 attached to the rotary shaft 52 and the number of contact portions 54 a to 54 c, 58 a, 58 b, 62 a included in the cam members 51, 56, 60 are arbitrary. Can be changed. By increasing the number of these combination patterns, it is possible to cope with a wider variety of paper widths. Further, the cam members 51, 56, 60 corresponding to the plurality of valves 37 may be integrally formed.

In each of the above embodiments, the volume of the first negative pressure chamber 39 may be smaller than the volume of the second negative pressure chamber 43.
In the above embodiment, for example, the suction holes 29 corresponding to the A4 size (size 1) paper 12 in the suction hole array 29a are communicated with one flow path, and the A4 size among the non-communication flow paths. The suction hole 29 corresponding to the A3 size (size 2) may be further communicated with one flow path, and a valve 37 may be provided in each flow path. Thereby, the structure of the switching means and its control can be simplified.

  In the above embodiment, the recording apparatus provided with the transport device is embodied in the ink jet printer 11, but is not limited to this, and other liquids other than ink (including liquid materials in which particles of functional material are dispersed) The present invention can also be embodied in a recording apparatus that ejects the ink. For example, for manufacturing liquid chips and biochips for spraying liquid materials containing dispersed or dissolved materials such as electrode materials and color materials used in the manufacture of liquid crystal displays, EL (electroluminescence) displays, and surface-emitting displays. It may be a liquid ejecting apparatus that ejects a biological organic material to be used, or a liquid ejecting apparatus that ejects a liquid as a sample that is used as a precision pipette. And a recording apparatus and a conveying apparatus can be applied to any one of these liquid ejecting apparatuses.

1 is a schematic diagram of a printer according to a first embodiment. FIG. 6 is a plan view showing an overlapping relationship among paper, a conveyance belt, and a support base. The cross-sectional schematic diagram of a valve and a cam. The block diagram of a control part. The cross-sectional schematic diagram of a valve and a cam. The cross-sectional schematic diagram of a valve and a cam. (A) is a top view of the cam member of 2nd Embodiment, (b) is a top view of the cam member, (c) is a top view of the cam member. The perspective view of a cam. The cross-sectional schematic diagram of a valve and a cam. The cross-sectional schematic diagram of a valve and a cam. The cross-sectional schematic diagram of a valve and a cam. The cross-sectional schematic diagram of the valve and solenoid of 3rd Embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Printer (recording apparatus) 12, 65a-65c ... Paper (recording medium), 17 ... 2nd conveyance part (conveyance apparatus), 19 ... 2nd drive pulley (conveyance means), 21 ... 2nd driven pulley (conveyance) Means), 23 ... second conveying belt, 24 ... recording head (recording means), 27, 64 ... support base (support member), 27a ... support surface, 28 ... vent hole (hole), 29 ... suction hole, 29a ... Suction hole array, 30 ... opening (suction opening), 33 ... fan (suction means), 36 ... valve body, 37 ... valve, 39 ... first negative pressure chamber, 40, 52 ... rotating shaft, 41, 51, 56 , 60 ... cam member, 43 ... second negative pressure chamber, 44 ... control section (control means), 49 ... paper edge sensor (detection means), 42, 54a to 54c, 58a, 58b, 62a ... contact section, 66 …solenoid.

Claims (10)

A support member having a support surface capable of supporting a recording medium and having suction openings of a plurality of suction holes formed on the support surface;
Suction means for sucking air from the suction opening by generating a negative pressure in the suction hole;
It is provided so as to individually correspond to each suction hole, and in the first valve state, air flow in the suction hole is allowed when the suction means is driven, and in the second valve state, it is more than in the first valve state. A valve that inhibits the flow of air in the suction hole when the suction means is driven;
Switching means for switching the valve state of the valve;
Transport means for transporting the recording medium sucked to the support surface side based on the negative pressure in the suction hole from the upstream side to the downstream side in the transport direction;
Detecting means for detecting the recording medium conveyed by the conveying means;
Control means for operating the switching means based on the detection result of the detection means,
The control means adjusts the valve state of the valve corresponding to the suction hole at the position where the tip of the recording medium passes during the conveyance of the recording medium by the conveying means in accordance with the passage timing of the tip of the recording medium. The second valve state is switched to the first valve state, and the valve state of the valve corresponding to the suction hole at the position where the rear end of the recording medium passes matches the passage timing of the rear end of the recording medium. The transfer device is characterized in that the switching means is operated so as to be switched. The air flow path further guides the air sucked from the suction opening of the suction hole to the suction means based on the driving of the suction means, and the air flow path is defined by the position of the valve as a boundary. A volume of the first negative pressure chamber, which is divided into a negative pressure chamber and a second negative pressure chamber and is formed between the suction means and the valve, is formed between the valve and the suction opening. The transfer device according to claim 1, wherein the transfer device is larger than a volume of the second negative pressure chamber. The support member is formed with a plurality of suction hole arrays in which the plurality of suction holes extend along a direction perpendicular to the recording medium transport direction at intervals in the recording medium transport direction. And
The transfer device according to claim 1, wherein the switching unit switches a valve state of the valve for each of the suction hole rows. The switching means is
A rotating shaft that the control means rotates based on a detection result of the detection means;
A cam member provided on the rotary shaft so as to be integrally rotatable,
The cam member displaces the valve body of the valve between a first position corresponding to the first valve state and a second position corresponding to the second valve state based on rotation of the rotating shaft. The conveying apparatus as described in any one of Claims 1-3 characterized by these. The cam member has a contact portion that contacts the valve body at the time of displacing the valve body to the first position in at least one place in the rotation direction of the rotation shaft,
The rotating shaft is provided with a plurality of types of the cam members having different numbers of the contact portions,
5. The transport device according to claim 4, wherein the control unit rotates the rotation shaft within a range of a rotation angle determined based on a size of the recording medium in a direction orthogonal to the transport direction of the recording medium. . The switching means is a solenoid that displaces a valve body of the valve between a first position corresponding to the first valve state and a second position corresponding to the second valve state. The conveyance apparatus as described in any one of 1-3. The control means sets the valve corresponding to the suction hole to the first valve state when the suction opening of the suction hole is covered by the recording medium conveyed from the upstream side to the downstream side for each suction hole. The conveying device according to claim 1, wherein the switching unit is operated so as to be switched to the first position. 8. The conveyance belt according to claim 1, wherein the conveyance unit is a conveyance belt in which a communication hole that can communicate with the suction hole by moving while sliding on the support surface of the support member is formed. The conveying apparatus as described in any one of them. Recording means for recording by attaching a recording material to the recording medium;
A recording apparatus comprising: the conveying apparatus according to claim 1 that conveys the recording medium. The recording medium supported by the support surface of the support member in which the suction openings of the plurality of suction holes are formed is sucked by the negative pressure generated in the suction holes and supported by the support surface, while upstream in the transport direction. A method for transporting a recording medium transported from the side to the downstream side,
Switching the suction hole at a position through which the front end of the recording medium to be conveyed passes to a first state in which the air flow in the suction hole is allowed;
Switching the suction hole at a position where the rear end of the recording medium passes to a second state in which the flow of air in the suction hole is hindered.

Images